It doesn't open on mac! :(
Sometimes Apple will not allow apps to run that are downloaded from Itch.
The easiest way to play is in your browser or by downloading and installing the game through the official itch.io app https://itch.io/app
The other way is to try open the app, then click ok on the dialog box that appears. Then go to System Prefs > Security & Privacy > General > Open anyway. This is for OS Catalina and above.